Parallelogram linkage operating means and integral contact terminal securing means for an oil circuit breaker



May 26, 1970 KlYoJl oGAwA 3,514,551

PARALLELOGRAM LINKAGE OPERATING MEANS AND NTEGRAL CONTACT TERMINAL SECURING MEANS FOR AN OIL CIRCUIT BREAKER KIVOII OGAWA.

INVENTOR BY wall/ai, 1.0 Pmub. sdij May 26, 1970 KlYoJl oGAwA 3,514,561

PARALLELCCRAM LINKACE OPERATING MEANS AND INTEGRAL CONTACT TERMINAL SECURING MEANS FCR AN CIL CIRCUIT BREAKER Filed Oct. 31, 1967 3 Sheets-Sheet 2 F/C i T8 /9 :cn/05| oCAwA,

INVENTOR BY wwnru Mfmuh. Mhjb May 26, 1970 KlYoJl oGAwA 3,514,551

PARALLELOGRAM LINKAGE OPERATING MEANS AND INTEGRAL CONTACT TERMINAL SECURING MEANS FOR AN OIL CIRCUIT BREAKER Filed Oct. 3l, 1967 3 Sheets-Sheet 3 f F/G (off) 73 (om KIYOII OGAWA INVENTOR BY CLL om. MM5

United States Patent O 3,514,561 PARALLELOGRAM LINKAGE OPERATING MEANS AND INTEGRAL CONTACT 'I'ERMINAL SECUR- ING MEANS FOR AN OIL CIRCUIT BREAKER Kiyoji Ogawa, Hitachi-shi, Japan, assignor to Kabushiki Kaisha Takahashi Denki Seisakusho, Motomiya-cho, Hitachi-shi, Ibaragi-ken, Japan Filed Oct. 31, 1967, Ser. No. 679,457 Int. Cl. H01h 33/ 68 U.S. Cl. 200-150 4 Claims ABSTRACT F THE DISCLOSURE A switch particularly for short circuiting heavy current, comprising a lid, an oil tank hermetically sealed by said lid, a pair of stationary contacts extending through said lid into the oil tank, a movable bridging conductor in said tank and opposed to said stationary contacts, a mechanism on which said bridging conductor is mounted for moving said conductor into and out of contact with said stationary contacts, said mechanism comprised of an operating handle and suspending link connected to a horizontal connecting rod, and two parallel vertical spindles connected to said horizontal connecting rod, and to a horizontal support, said pair of contacts each being bent at an appropriate angle to form top and bottom portions at an angle to each other, mounting members depending from said lid, and bolts extending through said top portions and said bottom portions into said mounting members, the bolts in the respective top and bottom portions lying on lines which intersect.

The present invention relates principally to a switch for a heavy D.C. low voltage current, for instance, for an electrolyser for the production of caustic soda. The switch according to the invention can be used to switch not only a low voltage but also a high voltage current while conducting a current.

By a heavy low voltage current is meant a heavy current on the order of 4 to 10 volts and 2,000 to 20,000 amperes. Of course, these numerical values arenot limitative but only exemplary.

The present invention will be explained in connection with an oil switch for electrolysers which comprises two stationary contacts forminga pair and a movable bridging conductor capable of touching or separating from said fixed contacts. The stationary contacts protrude downwardly from the inside of a lid of an oil tank in such a way that no displacement will occur, by taking advantage of the effect obtained by causing the line along which the` attaching means extend to intersect at an angle.

The movable bridging conductor is suspended opposite the stationary contact inside the lid, by means of a suspending mechanism including a relative position controlling mechanism and a smooth vertical motion guiding mechanism. Said suspending mechanism interlocks with an operational lever pivotally mounted on and extending outside the lid, whereby said movable bridging conductor can be brought into contact with the stationary contacts or separated therefrom.

The principal object of the present invention is to provide a novel, improved switch for heavy current, in which the contact between the stationary contacts and the movable bridging conductor in the closed circuit condition is stable and excellent.

Another object of the present invention is to provide a switch for heavy current, in which no slackening of clamping and no dislocation will occur, even when an external force is applied to the stationary contacts, whereby the contact conditions of the switch remain satisfactory when the contacts are closed.

Another object of the present invention is to provide an operating means for a switch for heavy current, in which the movable bridging conductor is guided so as to move vertically, smoothly and without pitching and rolling, whereby an exact bridging between a pair of stationary contacts is accomplished.

A further object of the present invention is to provide a switch for heavy current, wherein the position of the movable bridging conductor relative to the stationary contacts and the horizontal position of the movable bridging conductor can be easily adjusted to its optimum position.

A still further object of the present invention is to provide a short circuiting switch for electrolysers, in which when a plurality of electrolysers connected with a common electric circuit are in operation, and when one of the electrolysers is damaged, only the damaged electrolysers can be quickly short-circuited and disconnected from the circuit without stopping the operation of the other electrolysers.

Another object of the present invention is to provide a low priced short circuiting switch for heavy current, in which copper terminal conductor rods are omitted, and the required materials and the number of manufacturing steps are reduced.

A further object of the present invention is to provide a short circuit switch for heavy current, wherein when the circuit is closed, the main contact portions come into contact after -the auxiliary contact portions are brought into contact, while when the circuit is opened, the main contact portions separate before the auxiliary contact portions separate, whereby the damage to the main contact portion is held to a minimum.

A still further object of the present invention is to provide a short circuit oil switch for electrolysers, wherein the 4tank can be easily disconnected while the switch remains undisturbed, and the contact portions or the like can be inspected and adjusted and the oil can be exchanged.

Another object of the present invention is to provide a short circuit switch for electrolysers, which is small and convenient for handling.

In the following, the present invention isdescribed in detail with reference to the accompanying drawings in which:

FIG. l is a front longitudinal sectional view of a short circuit switch according to the present invention in the open circuit condition;

FIG. 2 is a sectional view on line IL-II of FIG. l;

FIG. 3 is a front longitudinal sectional view of a short circuit switch according to the present invention in the closed circuit condition;

FIG. 4 is a sectional View of line IV-IV of FIG. 3;

FIG. 5 is a front view, partially in section, of another embodiment of the invention in the closed circuit condition; and

FIG. 6 is a view of three short circuit switches of the present invention installed for simultaneous operation.

Referring to FIGS. l to 4, an oil tank 1 made of steel sheets or cast iron plates has a lid 2, all of which are coated with acid-proof paint. Hanger bolts 3 for said oil tank 1 are inserted through a ange 4 extending around lid 2 on one hand and ange 5 extending around the sides of the oil tank on the other hand, and the lid 2 and oil tank 1 are united by securing nuts 6 on bolts 3. A packing 7 is provided between the top of tank 1 and lid 2.

A pair, i.e. left and right hand side legs 8 depend from the under side of lid 2 for mounting terminal conductors which protrude from the under surface of lid 2, each having a vertical attaching surface 8a and an inclined attaching surface 8b.

A pair of terminal conductors 9 are provided simulta- 3 neously serving as a pair of stationary contacts, the lower portions of which are bent inwardly at the same angle as that formed between said vertical attaching surface 8a and the inclined attaching surface 8b, thereby forming a vertical portion 9a and an inwardly angled portion 9b. The vertical portion 9a of said terminal conductor rod is held between insulation plates 10 and 11, and attached to the vertical attaching surface 8a of said legs by means of bolts 13 inserted in an insulation tube 12 extending through the plates 10 and portion 9a. Similarly, the inwardly angled portion 9b of the terminal conductor rod is grasped between insulation plates 14 and 15 and attached to the inclined attaching surface 8b by means of bolts 17 inserted through an insulation tube 16. As is apparent from the above description, the axes of the bolts for attaching the terminal conductor rods intersect one another at an angle between bolts 13 and 17 which is the complementary to the angle between the vertical attaching surface 8a and the inclined attaching surface 8b. Therefore, in comparison with an arrangement wherein a straight portion is attached at two places, the overall securing force of the two bolts is greatly improved, and even when an unusually large external force is added Vto the upper projecting portion of terminal conductor rod 9, no loosening will occur in the attached portion, which feature has an important meaning. When a bus-bar is connected with terminal conductor rod 9, a very high external force acts on the portion of rod 9 projecting upwardly through the lid, so that loosening of the attached portion is liable to occur. If loosening takes pl-ace, the xed contact at the` lower end of terminal conductor will be dislocated, resulting in a bad influence on the operating of a short circuit switch.

According to the construction described above, since the axes of bolts 13 and 17 intersect, there is no fear of loosening at the attached portion, whereby the contact position is always correct.

As described above, the securing effect due to an angle between the two attaching portions is the largest at an angle of 90 and the effect decreases as the angle decreases. When required space and operational advantage are taken into consideration, the optimum angle will be found at approximtely 135, as is apparent from the drawings. Tap holes 18 for terminal conductors 9 are protected by insulation compound 19 and insulators 20 as is usual in machinery of this type.

A movable bridging conductor 21 is divided into several parts according to the current capacity. Each conductor part is mounted on two adjusting studs 23 and 24 mounted on a horizontal support 22. Between each conductor part, -and the horizontal support, is a compression spring 25 around each adjusting stud, by which spring 25 said conductor part is urged upwardly, the upper limit of the movement of which is restricted by adjusting nut 26 threaded onto the upper portion of each adjusting stud 23 and 24.

The horizontal support 22 is provided with large adjusting groove holes 27 in both ends, through each of which extends a threaded portion of the lower end of vertical spindles 28 and 29. The top and bottom of said threaded portions are secured to support 22 by nuts 32 and 33 and insulation plates 30 and 31, whereby the lower ends of vertical spindle 28 and 29 and the end-portions of horizontal support 22 are united. Further, each of the threaded portions in the holes 27 is positioned within an insulation tube 34.

The Iupper portions of vertical spindles 28 and 29 are slidably positioned in guide-holes 37 and 38 of lguidetubes 35 and 36 provided on lid 2, and a long vertical ventilation groove 39 extends downward along the upper end of the portion of said vertical spindle within the guide tube. The inner diameters of said guide holes 37 and 38 are slightly larger than the outer diameters of vertical spindles 28 and 29 in order to assure an exact vertical motion of the vertical spindles. However, the inner diameter of either one of guide holes 37 or 38, for instance, in FIG. 2, the inner diameter of guide hole 37, can be slightly larger than that of the other guide hole 38 to provide a clearance between the spindle 28 and guide hole 37, thereby enabling exact and smooth vertical sliding of vertical spindles 28 and 29, while binding in the form of mutual interference of the sliding of the spindles is avoided.

A horizontal connecting rod 40 connects said two vertical spindles 28 and 29, being secured thereto by pins 41. A parallelogram linkage is formed by said horizonal connecting rod 40, the horizontal supporter 22 and the two vertical spindles 28 and 29. A suspending link -42 has a lower end connected to said horizontal rod 40 at the middle by pin 43, and the upper end of the link 42 is connected to the free end of crank 44 by pin 45. A rotary shaft 46 has the other end of crank 44 mounted thereon. The rotary shaft 46 is pivoted in crank-protection cover 47 secured to the upper portion of lid 2. An operating handle has the lower portion bifurcated so as to extend around said protection cover, and the lower ends are fixed to said rotary shaft 46.

Said suspending link 42 is curved in a hook shape as illustrated, and constructed in such a way that when operating lever 48 is pulled as shown in FIG. 4 the center of pin 45 moves to one side (the right hand side in FIG. 4) of a line assuring that the movable bridging conductor 21 will remain in the raised position.

The lower ends 49 of said terminal conductors 9 act as xed contacts and the contact surfaces are provided, if needed, with layers of silver. Both shoulder portions 50 of the movable bridging conductors 21 act as contacts, corning in contact with said fixed contacts, said portions being provided with layers of silver.

Stationary contacts 51 which form part of auxiliary contact means are xed to the lower surfaces near the lower ends of terminal conductor rods 9. Movable contacts which form part of auxiliary contact means are formed on the upper ends of terminal rods 54 secured on the free ends of conductors S3 and are iixed at one end to the bottom of the movable bridging conductors 21, being held in contact-guides 55, one end of each guide being lixed to the bottom of a movable bridging conductor 21 together with said conductors 53. Said terminal rods 54 are slidable in the free ends of the guides 55 in order to guide the vertical motion of terminal rods 54. A spring 56 is provided around each rod 54 for lifting the auxiliary contacts 52.

Said auxiliary contact means are so arranged that when movable bridging conductors 21 are raised, the auxiliary contact means make contact before the main contact portions, and only then do the main contact portions come in contact. Naturally, when the switch is opened, Ifirst the main contact portions separate, and then, the auxiliary contact means separate.

With such a construction, when operating lever 48 is moved to the open position (or OFF) as shown in FIGS. l and 2, the movable bridging conductors 21, the vertical spindles and horizontal support descend to break the contact of the bridging conductor 21 with the stationary contacts.

When operating lever 48 is turned in the closing (or ON) direction, the horizontal connecting rod 40 is raised through rotary shaft 46, crank 44 and suspending link 42. Accordingly, the vertical spindles 28 and 29 and horizontal support 22, which constitute a parallelogram linkage together with said horizontal connecting rod 40, are also raised. As shown in FIGS. 3 and 4, the movable bridging conductors 21 held by horizontal support 22 are brought into contact with the pair of stationary contacts under pressure to bridge the gap between the two stationary contacts. Because horizontal connecting rod 40 connected at the center with suspending link 42, horizontal support 22 holding the movable bridging conductor 21, and the two vertical spindles 28 and 29 constitute a parallelogram linkage, and since the upper portion of the vertical spindles 28 and 29 are slidable in guide holes 37 and 38 in guide tubes 35 and 36 provided on lid 2, when said movable bridging conductors are lifted or lowered, said movable bridging conductors can move vertically without rolling or pitching to correctly bridge the gap between the stationary contacts. Since one or the other of said guide holes 37 and 38 is made slightly larger in the diameter than the other, a clearance is provided between the vertical spindle and the wall of the guide hole, and there is no binding due to mutual interference of vertical spindles 28 and 29, so that very smooth vertical motions occur. Further, in the present invention, the movable bridging conductors are mounted on two adjusting studs 23 and 24 and a compression spring 25 is arranged between each movable bridging conductor and the horizontal supports. An adjusting nut 26 is provided for each adjusting stud. Accordingly, the horizontal position of the respective movable bridging conductors as well as the level of each movable bridging conductor can be made uniform by adjusting theadjusting nuts.

On the other hand, horizontal support 22 is not connected with vertical spindles 28 and 29 on both extremities of support 22, but adjusting groove holes 27 are provided, and nuts 32, 33 clamp insulation members 30 and 31 against the support 2 to hold the ends thereof. Accordingly, the connection between vertical spindles 28 and 29 and horizontal support 22 can be adjusted after slackening the nuts 32 or 33, that is, the relative position of both can be adjusted so that contacts 50 of the movable bridging conductors 21 will come in contact -with contacts 49 on the stationary contact correctly.

The above mentioned adjustment of the horizontal position and the level of each movable bridging conductor as well as the relative position of the stationary contacts is important for maintaining stable and satisfactory contact. However the stationary contact can be fixed in a non-movable position, because stable and satisfactory contact can not be achieved when the relative position of the movable bridging conductors and the stationary contacts as well as the horizontal positions thereof are not correct. In the present invention, rst the stationary contacts are fixed in immovable positions by placing the fastening means at an angle, and thereafter because the horizontal position and the relative position of movable bridging conductors to said stationary contacts can be adjusted, the closed caontact conditions can be made remarkably stable and satisfactory. Moreover, the adjustment can be effected easily and exactly during assembly of the switches. anni after installation, adjustment can be effected easily after removal of the oil tank.

FIG. 5 illustrates a modification of the short circuit switch shown in FIGS. ll to 4.

In this embodiment the terminal conductors rod 9` of FIGS. l to 4 are not used, but instead the ends of aluminum bus bars, copper bus bars or the like are introduced into the tank, and certain accompanying changes are made in the construction of the parts of the stationary contacts. Except for these modifications, the construction of this embodiment is identical with that shown in FIGS. l to 4. Hence, only the modifications will be described.

Referring to FIG. 5, a bus bar 57 of aluminum or copper orthe like is provided with an end 58 which is flexible. The bus bar has an end 59 having the front end portion bent similarly to the bend in the embodiment shown in FIGS. l to 4, to provide a vertical portion 59a and a bent portion 59b. The vertical portion 59a is held between the insulation members and 11 as in the first embodiment, and is fixed by bolt 13 having an insulation sleeve 12 therearound on the vertical surface 8a depending from the bottom surface of lid 2. Bent portion 59h has attached thereto a stepped stationary contact 461, an intermediate thin conductor sheet 60 being provided between contact 61 and bent portion 59a. These are held between insulation members 62 and 63 and are mounted on an inclined surface 8b by two bolts 65 having an insulation sleeve 64 therearound. The part of bus bar passing through the lid is protected by insulation compound 19 and insulator 20. Other reference numbers in FIG. 5 designate the same parts as in FIGS. 1 to 4.

According to the present embodiment, the terminal rod 9 is not used, and since the end of bus bar is directly introduced and fixed in the switch, the material needed can be lreduced correspondingly in comparison with the embodiment shown in FIGS. l to 4, and the connection by clamping the end of bus bar and the terminal conductor rod to each other is economical.

An example of an installation using the short circuit switch of the present invention is shown in FIG. 6. A supporting rim `66 extending outwardly from flange 4 of lid 2 rests on the upper surface of stand 67, and is fixed thereto by a bolt 68 or the like. The required number of switches (3 in the case of FIG. 6) are arranged in a straight line, and each of the operating levers 48 thereof is connected to a common operating rod 69 by a pin 70. The end of said operating rod 69 is connected to an operating handle 73 by a pin 74; and the operating handle is pivotally mounted on an operating support 71 by pin 72. In such a way, all the switches can be opened or closed all at once by moving the operating handle 73 to the ON or OFF position as shown in the drawings.

In FIG. 6, a hand operated arrangement is shown. However, an electromagnetically operated or a cylinder operated arrangement in which oil pressure or air pressure is utilized can be used instead.

When, as shown in FIG. 6, a short circuit switch is installed on a stand, the oil tank 1 can be removed by removing nuts 6 at the lower end of bolts 3, so that inspection as well as adjustment, etc. can readily be performed.

What is claimed is:

1. A switch particularly for short circuiting heavy current, comprising a lid, an oil tank hermetically sealed by said lid, a pair of stationary contacts extending through said lid into the oil tank, 'a movable bridging conductor in said tank and opposed to said stationary contacts, a mechanism on which said bridging conductor is mounted for moving said conductor into and out of contact with said stationary contacts, said pair of contacts each being bent at an appropriate angle to form top and bottom portions at an angle to each other, mounting members depending from said lid, and bolts extending through said top portions and said bottom portions into said mounting members, the bolts in the respective top an-d bottom portions lying on lines which intersect, said mechanism for moving said conductor into and out of contact with said stationary contacts comprising two parallel vertical spindles, a horizontal connecting rod connected between said spindles, and a horizontal support extending between the lower ends of said spindles, said spindles, connecting rod and support forming a parallelogram linkage, a suspending link depending from said lid and extending through said lid, an operating handle connected to said suspending link for raising and lowering the suspending link, and guide tubes on said lid having guide bores rtherein in which the upper ends of the spindles are slidably positioned.

2. A switch as claimed in claim 1 in which said suspending link is pivotally connected to the center of said horizontal connecting rod, a shaft rotatably mounted on the outside of said lid and to which said operating handle is fixed for rotating said shaft, a crank on said shaft, the free end of said crank being pivotally connected to said suspending link, said suspending link being curved and the pivotal connection between the crank and the suspending link lying on the opposite side of a Vertical line between the shaft 'and the pivotal connection of the Suspending link lying on the opposite side of a. vertical line mechanism is in the raised position.

3. A switch as claimed in claim 1 in which said spindles each have a longitudinal groove in the surface thereof which lies within said guide tubes, and one of the bores in said guide tubes is slightly larger in diameter than the other to provide a greateai clearance for the spindle sliding therein.

4. A switch as claimed in claim 1 in which the said ends of said spindles at said horizontal support are threaded, said horizontal support having holes in the ends thereof through which said threaded portions of said spindles pass, insulation members on the top and bottom of said horizontal support at said spindles, nuts on said threaded portions of said spindles clamping said ins-ulation members against said horizontal support for holding said horizontal support on said spindles, said horizontal support having upstanding threaded pins thereon, said pins extending through said bridging conductor, spring means around said pins urging said bridging conductor upwardly, and nuts on said pins for securing said bridging conductor in position against the action of said springs,

whereby the position of the bridging conductor and horizontal support can be adjusted.

References Cited UNITED STATES PATENTS ROBERT K. SCHAEFER, Primary Examiner R. A. VANDERHYE, Assistant Examiner 

